This paper intends to investigate whether the speed of a transition process influences the degree of HRM developments in transition economies. We therefore focused our investigation on the HRM practices in two transition countries - Slovenia and Serbia, which used to be constitutional parts of the former Yugoslavia and used to share the same political and cultural background for many years. The analysis was focused on the following areas of HRM: the role of the HR function, HRM strategy involvement, training and development, performance measurements and rewards, employee relations and the role of trade unions. The research findings show that the HRM policies and practices in Serbia and Slovenia, regardless of the shared background, diverge in all analyzed aspects. The results obtained confirm that the transition process, per se, may explain almost all differences between HRM practices in Serbia and Slovenia.